// 构建一个命名空间
namespace XX{
    export class Person{
        _name:string="张三";
        constructor(n:string){
            this._name = n;
        }
        say(){
            console.log(this._name);
        }
    }
}
namespace YY{
    class Person{
        _name:string="张三";
        constructor(n:string){
            this._name = n;
        }
        say(){
            console.log(this._name);
        }
    }
}